Drilling fluid loss control via implementing the FMI and DSI logs to protect environment

Abstract

Implementing the drilling fluids in drilling operations is of paramount importance owing to the variety of applications and benefits they provide. Materials added to drilling fluid could cause numerous environmental problems in soil and water resources, and these problems are more pronounced in offshore as compared to land fields. Heavy metals such as mercury, barium, arsenic, lead, and nickel exist in drilling fluid, which bring detrimental damages to the environment. Moreover, heavy metals exist in oil-based muds due to presence of oil where their nickel and vanadium are much greater than other heavy metals. Additive materials and heavy metals existing in drilling fluid could pose irreparable environmental damage if fluid loss into the formation occurs. Regarding to the fact that drilling fluid loss occurs via the open fractures in the wellbore, the main aim of this study is to evaluation of wellbore fractures via implementing the FMI log and fracturing pressure using the slowness of compressional and shear waves. A total of 61 fractures in Dalan formation and 72 fractures in Kangan formation are interpreted and fracturing pressure for these formations, ranges between 8400 and 9450 psi. Implementing the results obtained from this study, drilling fluid loss into the formation and subsequent environmental damage could be prohibited via controlling the pumping pressure and density variation of drilling fluid in accordance with the formation fracturing pressure.

Natural fracture characterization and in situ stress orientation analysis using Fullbore Formation Micro Imager (FMI): a case study on the X oil field, Kurdistan Region, Iraq

“…Understanding in-situ stress is essential for oil and gas exploration and production, particularly for wellbore stability, hydraulic fracturing, flooding patterns, and fluid flow in fractured reservoirs [1][2][3][4][5]. In-situ stress can be detected using various theoretical, experimental, and field methods, such as overcoring, hydraulic fracturing, focal-mechanism solution, borehole breakout, and geological analysis [6][7][8]. It is challenging to employ overcoring and hydraulic fracture procedures at deep depths where there may be violent breakouts, high pressures, or high temperatures.…”

“…Numerous studies have demonstrated that for a vertical or nearly vertical well, the orientation of BOs reflects the direction of the minimum horizontal principal stress, and that of DIFs indicates the direction of the highest horizontal principal stress [10][11][12][13]. Consequently, the identification of BOs and DIFs associated with the in-situ maximum horizontal stress and the directions of the tremendous horizontal stress have been widely accomplished using borehole image logs [7,14,15]. Due to the advancement of borehole electrical imaging technology, geoscientists now have access to valuable high-resolution data on the features and specifics of the formations that exploration wells have been able to intercept [16,17].…”

Fracture analysis and in situ stress estimation of a gas condensate field in Persian Gulf using FMI and DSI image logs

“…The "X" field, as a northern extension of Qatar's North Gas Field, is located in the Persian Gulf about 175 km from Kish Island and 105 km from Qatar [29] (Fig. 1).…”

“…The log data were analyzed and evaluated using the MULTIMIN interpretation method for all formation units in well A [29]. Generally, the amount of shale has been neglected due to its low percentages from the gamma ray (GR) log of K1, K2, K3, and K4 units.…”

“…9. In the figure, the monopole, projection and semblance are shown to describe the time to receive the data, average frequency used in filtering the data and presenting the pressure, shear and stonely waves [29].…”